JP2005206893A - Connector terminal, and surface reforming method for connector terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide connector terminals each composed of copper or a copper alloy having a corrosion resistant finished surface free from a secular change and whose contact resistance is not increased as well by being finished in accordance with prescribed treatment working without the application of nickel substrate plating, e.g., as a copper diffusion barrier, the protection of the substrate plating and the formation of an intermediate plating layer corresponding to the pinholes of gold plating and also without requiring gold plating, and to provide a surface reforming method for connector terminals composed of copper or a copper alloy. <P>SOLUTION: The surface of a comb-shaped producing member for connector terminals each composed of copper or a copper alloy is irradiated with the pulse of an electron beam having energy density at which the surface layer part is instantaneously melted by the irradiation for a short irradiation time limiting the energy quantity to the one at which the melted part is immediately resolidified for one or more times, thus a corrosion resistant-wear resistant copper amorphous layer is formed on the surface part so as to be finished. In this way, surface treatment is made needless. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement in a connector terminal whose base is made of copper or a copper alloy, and a surface modification processing method for the connector terminal.

  Conventionally, as a connector terminal, a nickel plating layer as a copper diffusion barrier is applied to a base made of a copper alloy such as brass, beryllium copper, phosphor bronze, or white, and the surface is further improved in electrical characteristics and corrosion resistance. Many were excellent gold-plated, and some were tin-plated. Gold is excellent as an electrical property and corrosion resistance, so it is ideal as a metal to be plated on the surface of the terminal material. However, it is extremely expensive. Attempts have been made to limit the amount of use as much as possible, for example, by limiting the plating range only to the parts necessary for the function.

  However, reducing the gold plating thickness increases the number of pinholes, which increases the risk of corrosion of the underlying metal. In partial gold plating, the exposed nickel plating surface is directly corroded. As a result of exposure to the environment, there is a problem that the corrosion is easily corroded, and the corrosion product of nickel or base copper migrates to the gold plating surface and causes an increase in contact resistance, thereby impairing reliability. For this reason, it has been desired to develop a terminal material having excellent corrosion resistance even with a thin gold plating thickness or partial plating.

As a solution to this, a nickel plating layer as a copper diffusion barrier having a thickness of 1 to 4 μm as a whole and a tin-nickel alloy plating layer as an intermediate layer having a tin content of 50 to 80 wt% are sequentially formed on the entire surface of the copper alloy substrate. Further, it has been proposed that a gold plating layer be provided on at least the surface of the tin-nickel alloy plating layer that serves as a contact (see Patent Document 1).
It has also been proposed that instead of the intermediate tin-nickel plating layer, sulfide nickel sublite plating that is easier to oxidize than the underlying nickel plating layer is applied as an intermediate layer, and finally gold plating is applied as an upper layer. (See Patent Document 2).
In addition, instead of providing the plating layers as the intermediate layers, an organic solvent containing two special components (A) and (B) for the pinhole of the gold plating layer provided as the uppermost layer. It has also been proposed to seal with a sealing treatment liquid made of a liquid (see Patent Document 3).

  However, first of all, even if there is a little more or less required amount of gold or gold alloy, there is no change in the use of expensive gold. Further, since the formation of the intermediate layer by plating described above requires a sealing treatment, further development is desired.

  By the way, as a contact for a printed circuit board connector, brass or phosphor bronze is used as a base material, and this is replaced with Au plating or Sn plating to prevent oxidation. It has been proposed to use a copper alloy composed of ˜4% Ni, 0.2 to 1.5% Si, 0.05 to 0.25% Mg, and the balance Cu, but its practical use is not certain ( Patent Document 4).

JP-A-63-121893 Japanese Patent Laid-Open No. 06-200395 Japanese Patent No. 2520981 Japanese Utility Model Publication No. 05-023433

  Therefore, the present invention uses copper or a copper alloy as a connector terminal, and forms a nickel base plating as a copper diffusion barrier or the like, and forms an intermediate plating layer corresponding to the protection of the base plating and a pinhole of gold plating. And a connector terminal having a finish surface that is corrosion resistant, does not change over time, and does not increase contact resistance by finishing by a predetermined processing without further gold plating, and copper or copper The object is to propose a method for modifying the surface of a connector terminal made of an alloy.

  The objects of the present invention are as follows: (1) The surface of a connector terminal made of copper or a copper alloy has an energy density at which a surface layer portion is brought into a predetermined dissolved state by irradiation, and the dissolved surface layer portion is dissolved. By a surface modification processing method for a connector terminal in which a copper amorphous layer is formed on the surface portion by irradiating at least once with a pulse of an electron beam having a short irradiation time, which is limited to the energy irradiation amount that is immediately re-solidified. Achieved.

In addition, the object of the present invention described above is (2) at least on a surface portion which becomes a contact surface of a connector terminal made of copper, a copper alloy, or a copper or copper alloy plated with a required metal or alloy,
The diameter Lr of the cross section perpendicular to the irradiation axis is Lr = x × 10 mm (where x = 0.1, 0.2, 0.3,... 0.5,... 0.8,. 1.0, 2.0, ... 5.0, ... 7.0), the energy density Ed is, Ed = 0.1~10J / cm ^2, a pulse beam of the pulse time width .tau.s is, .tau.s = Achieved by a surface modification processing method for a connector terminal in which a 0.05 to 5.0 μs electron beam pulse is irradiated at least once to form a copper amorphous layer as an electrical contact surface on the surface portion. Is done.

  The object of the present invention is as follows: (3) The surface of the connector terminal made of copper or a copper alloy has an energy density that instantaneously dissolves the surface layer portion by irradiation, and the melted surface layer portion dissolves. This is achieved by irradiating a pulse of an electron beam with a short irradiation time limited to the amount of energy to be re-solidified at least once to form a copper amorphous layer on the surface portion and finishing the surface to provide a connector terminal. The

Further, the object of the present invention described above is as follows: (4) A surface portion that becomes at least a contact surface of a connector terminal made of copper, a copper alloy, or a copper or copper alloy plated with a required metal or alloy is provided on an irradiation axis. The diameter Lr of the cross section perpendicular to Lr = x × 10 mm (where x = 0.1, 0.2, 0.3,... 0.5,... 0.8,. 0, 2.0,..., 5.0,... 7.0), the energy density Ed is Ed = 0.1 to 10 J / cm ² , and the pulse time width τs of the pulse beam is τs = 0. This is achieved by irradiating a pulse of an electron beam of 05 to 5.0 μs at least once to form a copper amorphous layer as an electric contact surface on the surface portion to finish the surface to be a connector terminal. Is.

  Another object of the present invention is (5) a contact portion for electrical connection such as a connector, plug, jack, socket, switch, or relay, and the contact portion or the entirety thereof is copper or a copper-based alloy, iron Alternatively, in an electronic mechanism component made of an iron-based alloy, or titanium or a titanium-based alloy, the surface of the contact portion is used as an irradiation beam, and the surface layer portion has an energy density that melts, and the melted surface layer portion is minute after melting. Irradiate at least one electron beam pulse with a short irradiation time limited to the amount of irradiation energy to be resolidified in a short time to form an amorphous layer of contact metal member with improved surface roughness on the surface layer portion. This is achieved by forming a contact for an electronic mechanism component formed and finished with a surface.

  According to the present invention (1) to (4), a pulse of an electron beam having a specially required spread, a high energy density, and an extremely short irradiation duration is applied to a connector terminal made of copper or a copper alloy. Irradiated at least once to form an amorphous layer or film of copper, the surface roughness is significantly improved, wear resistance is increased, and corrosion resistance such as oxidation resistance is achieved. It is possible to obtain a connector terminal having excellent characteristics that lasts without deteriorating electrical characteristics such as contact resistance.

  And according to the present invention, at least the contact portion and its surroundings, or most of the contact side, with respect to the material having the terminal portion in a comb-teeth shape by press punching from a copper plate or copper alloy plate adjusted as a connector terminal material In summary, it is the length that forms a thin copper amorphous layer on the surface by irradiating the required number of pulses of the electron beam, so that the nickel plating of the base as a copper diffusion barrier, like the conventional connector terminal, There is substantially no need for intermediate plating or gold plating of tin-nickel alloy for protecting the underlying nickel plating, and gold plating for protecting the underlying and maintaining the electrical properties, and no expensive gold is required. Since there is no consumption, the equipment and the use of the equipment are easy to manufacture, easy to handle, and generally less manpower and time-consuming to manufacture. Next, the manufacture of the connector terminals, are those which may revolutionize provided.

  Further, according to the present invention (5), the present invention is not limited to one electronic mechanism component called a connector terminal, but is applied to a contact of an electrical connection part such as a similar plug, jack, socket, switch, or relay. Further, the target material for the surface modification processing is not limited to the copper or copper alloy such as oxygen-free copper, but the copper alloy, iron or iron alloy, or titanium or titanium. It can be applied to a contact made of a base alloy or various contact materials to further contribute to improving its performance.

  FIG. 1 shows, in a mass production process of the embodiments of connector terminals 31-1, 31-2, 31-3,... 31-n, stamped from a strip 31 made of oxygen-free copper or brass by a press, for example. It is an enlarged plan view of a part of a production member 31A. Then, after this press working, the surface is treated to be properly polished and then nickel-plated and then gold-plated on the surface. The production member 31A is installed on the processing table in the processing housing portion of the vacuum housing device of the surface modification processing device for a special metal member using an electron beam, which will be described in detail later, and a connector terminal 31-1, 31-2, 31-3,... 31-n, or at least the end portion on the side where the contact is present, and at least the surface on the side where the contact is present, the surface layer portion is instantaneously dissolved in a predetermined state by irradiation. And at least one pulse of an electron beam with a short irradiation time, usually limited to the amount of energy that the melting surface layer portion resolidifies immediately after melting, usually It is for irradiating a desired plurality of times at a short time of about the order.

  Hereinafter, an example of the surface modification processing method and apparatus using the electron beam having a large cross-sectional area will be described. FIG. 4 is a cross-sectional view of the apparatus showing an outline of the entire configuration, 1 is a vacuum housing, 6 is an annular anode, 8 Is a large area cathode such as a bundle of titanium (Ti) wires, S is an electron acceleration space, 5 is a magnetic field applying means comprising upper and lower solenoid coils, and 14 is a beam collector. The vacuum housing 1 includes a cylindrical beam housing portion 1A that houses an electron beam generating portion, and a processing housing portion 1B that houses a collector 14 and the like that receive electron beam irradiation. The beam housing portion 1A is an electron housing. The processing housing portion 1B is disposed so as to irradiate the beam in the vertical direction, while the processing housing portion 1B causes the workpiece 12 (production member 31A) on the collector 14 to be in a horizontal direction perpendicular to the vertical irradiation electron beam 11. It is attached and collected on a turntable 13 or a linear 1-axis or orthogonal 2-axis table so that it can be moved or fed.

  The rotary table 13 includes a circular plate 13A around which a collector 14 is attached, a rotary column 13B that attaches and supports the circular plate 13A to the processing housing part 1B, and a rotary column that is airtightly attached to the wall of the processing housing part 1B. A rotary motor 13C is provided so as to drive the rotation of 13B externally, and is configured so that the work 12 mounted on the required collector 14 can be positioned at the processing position PA where the electron beam 11 is irradiated. Yes.

A scroll pump 2 and a turbo molecular pump 3 are connected to the vacuum housing 1 via flow control valves 2A and 3A, respectively, and a gas cylinder 15 such as argon (A _r ) is connected to the vacuum housing portion 1 (not shown). By connecting through the pressure regulating valve 4 that is controlled so that the gas pressure detected by the installed vacuum sensor becomes the set gas pressure, the inside of the vacuum housing portion 1 is once in a vacuum state of 1 × 10 ⁻² Pa or less. After that, for example, a predetermined low gas pressure state of about 0.3 to 0.5 × 10 ⁻¹ Pa is maintained.

The processing apparatus shown in FIG. 4 is provided with three pulse power sources using ordinary capacitors as shown in FIGS. First, the first pulse power supply 16 stably traps the discharge in the low-pressure gas accompanied by the formation of the anode plasma 7 between the cathode 8 and the anode 6 and the collector 14 in the electron acceleration space S where the cathode 8 and the anode 6 face each other. As shown in FIG. 6, a plurality of solenoids 5, 5 excitation capacitor charging / discharging pulse power sources provided in the electron beam irradiation axis direction forming the magnetic field space shown in FIG. 6 so as to surround the electron acceleration space S, Specifically, for example, a capacitor of about 1000 μF is charged to about 1 to 2 KV and discharged at a discharge peak current of about 100 to 200 A and a pulse width of about 10 to 20 ms, so that the confined magnetic field, for example, 4.4 KO _{e is used.} The annular anode 6 is positioned between the upper and lower solenoids 5 and 5.

  Next, the second pulse power source 17 is applied to the cathode 8, the anode 6 and the collector 14, and the low pressure gas discharge accompanied by the anode plasma formation of the low pressure gas ionization in the region of the electron acceleration space S in which the confinement magnetic field is formed. Capacitor charge / discharge pulses for generating glow discharge, specifically, for example, a capacitor of about 5 μF is charged to about 4 to 5 KV, a discharge peak current of about 50 to 150 A, and a pulse width of about 10 to 100 μs, A delay of about 20 .mu.s to 5 ms after the start of discharge by switching on of the first pulse power supply, waiting for a sufficient magnetic field formation to switch on the discharge, thereby generating a low-pressure gas glow discharge accompanied with the formation of the anode plasma 7. It is a pulse power supply.

  The third pulse power source 18 has a large area energy density from the low-pressure gas discharge region accompanied by the formation of the anode plasma 7 in the confined magnetic field by the first pulse power source 16 and the second pulse power source 17. In order to generate and irradiate a short pulse of a moderately high electron beam 11, the rise is, for example, a pulse with a short rise time of about 5 to 10 ns, specifically, for example, a capacitor of about 3 μF is charged to about 20 to 60 KV Then, at a discharge peak current of about 5 to 25 KA, a low-pressure gas discharge was generated with a very short pulse width of about 1 to 5 μs, delayed by about 10 to 100 μs after the start of discharge by switching on the second pulse power source. By switching on after waiting for this, a negative high voltage pulse with a high rise is applied to the cathode 8, and an ion beam from the anode 6 is applied. A high-density cathode plasma is formed on the surface of the cathode 8, and a high-density electron beam 11 generated by the high-density cathode plasma and electrons from the cathode 8 is passed through the anode plasma 7 through the ring of the anode 6, The collector 14 is irradiated.

In such a large-area pulsed electron beam 11, the energy density of the electron beam 11 is about 0.1 to 10 J / in for the surface finishing of the metal material by irradiation and / or the modification of the amorphization of the surface. cm ² and about, because continuous irradiation time are those within a short few .mu.s, the electron beam irradiation area of the surface of the workpiece 12, and when repeatedly irradiated predetermined plurality of times, the diameter of the workpiece 12 surface of the electron beam 11 When processing a larger area sequentially by scanning, it is necessary to recharge the first to third pulse power supplies 16 to 18 to repeat generation and irradiation of the pulsed electron beam. In the case of the power supply configuration as described above, it is desirable that the specifications be such that the irradiation can be repeated repeatedly at intervals of about 5 to 10 s or shorter than that, from the purpose and effect of processing. That.

  According to the above configuration, the second power source 17 is a pulse power source, and the electric field due to voltage application between the anode 6 and the cathode 8 is not always, and there is no active supply of thermoelectrons. The above plasma formation is not easy, but for this reason, prior to the voltage application between the anode 6 and the cathode 8 by the second power source 17, a magnetic field is generated by the excitation of the solenoids 5 and 5 by the first pulse power source 16, thereby generating a low-pressure gas. The natural electrons existing inside are rotated so as not to escape from the electron acceleration space S. It should be noted that, when a pulse voltage is applied by the second pulse power source 17, the initial charged particles for starting the ionization are generated by (1) utilizing the electric field concentration of the minute protrusions of the cathode 8 and (2) the cathode 8 Auxiliary means such as (3) irradiate light such as ultraviolet rays to produce photoelectrons, (4) generate charged particles by another particle source, and inject them, and operate. You may make it make it.

  Here, when the anode magnetic field is applied from the second pulse power source 17 between the anode 6 and the cathode 8 when the working magnetic field becomes substantially maximum as the discharge of the capacitor progresses, the electrons captured in the magnetic field are By drawing a spiral, the frequency of collision with gas molecules increases and ionizes by colliding with gas molecules, and the generated electrons and positive ions move in opposite directions and repeat ionization. At this time, electrons quickly pass between the anode 6 and the cathode 8, whereas positive ions have a low mobility, so that some or more remain in a short time, resulting in distortion of the electric field. That is, the number of positive ions increases around the cathode 8, which tends to strengthen the electric field on the cathode 8 side and advance the discharge. If the positive ions are excessive with respect to the electrons, a potential difference is generated between the anode 6 and the cathode 8, and the electrons directed to the anode 6 are trapped there. As a result, anode plasma 7 is generated near the anode 6 and grows toward the cathode 8 while eliminating the electron trap.

  In the anode plasma 7 portion, the positive ions and the electron density are almost the same, so there is almost no space charge electric field, and the electron flow is carried to the anode 6 by a very low uniform electric field. On the other hand, in the vicinity of the cathode 8, positive ions necessary for creating a steep electric field at the same time as creating an electron flow necessary by ionization occur. These positive ions consist of positive ions generated by ionization and positive ions flowing from the anode 6 side. The positive ions collide with the cathode electrode 8 and knock out electrons from the electrode. These electrons collide with gas molecules and ionize them, and these electrons are repeated one after another, thereby generating primary electrons, secondary electrons, tertiary, and so on.

  In this way, the cathode plasma 9 is formed in a portion where electrons are sufficiently propagated and become approximately the same amount as the positive ions, and has the effect of a buffer function for maintaining a steep electric field. The anode plasma 7 and the cathode plasma 9 In the middle, the electric field rises slightly, and serves to prevent recombination and to slightly ionize to compensate for dissipated charged particles. That is, it is considered that electrons are generated and propagated in the portion of the strong electric field around the cathode 8, and the cathode plasma 9 and the anode plasma 7 form a passage of electrons having good conductivity.

In this state, the cathode potential is changed to a deep negative potential by applying a pulse voltage having a short duration (1 to 5 μs) of a high negative voltage (50 to 60 KV) with a short rise time of 5 to 10 ns described above. When lowered, the electric field around the cathode 8 becomes steeper, the electrons and ions due to ionization proliferate explosively, and a large energy density (0.1 to 1.0 J / cm ² or more) passing through the cathode plasma 9 and the anode plasma 7 The electron flow having a wide area is irradiated onto the work 12 on the collector 14 through the annular anode 6.

  The irradiation time of the electron beam is a factor determined from the physical (physical properties) conditions of the surface modification of the workpiece 12 to be processed. This is because the electron determined by the hardness of the workpiece 12 and the electron energy (KV) is the material. Depends on the depth of penetration of the material and the thermal conductivity of the material. Note that the above is a case where the surface of the material is amorphized by a method of rapidly heating the surface of the material and then rapidly cooling. In general, a light metal or a metal with good heat conduction is an electron beam. It shortens the irradiation time.

  In order to make the energy distribution density of an electron beam having a large cross section uniform, it is important that the electric field around the cathode 8 is uniform. For this purpose, the cathode plasma 9 and the anode plasma 7 are combined. For this purpose, it is important to form and form a magnetic field for uniformly confining plasma. When the discharge space is at a low gas pressure (about 1 Pa or less), the mean free path of electrons becomes long, and the chance of collision for ionization decreases, so that it is difficult to generate and maintain plasma. As a method for enabling this, since the method using the magnetic field is effective for confining the plasma, it is useful for generating and maintaining the plasma, but not necessarily effective for making the plasma uniform. That is, for example, when the magnetic field strength is increased, electrons are concentrated in the central portion, and it is difficult to uniformize the plasma having a large cross section.

The pulse of the large-area electron beam has an energy density at various locations in the irradiation region of the electron beam, the capacitor charging power supply voltage of the first pulse power supply that determines the excitation current of the solenoid 5 is the capacitance of the capacitor, or to be able to change settings in the range of approximately 0.1 J / cm ² to 10J / cm ² primarily by setting switching of the anode voltage in the voltage of the capacitor charging power supply of the second pulse source is a glow discharge generation power of the electron beam generating section However, since the large-area large-energy electron beam pulse generator shown in the drawing is an electron beam generator using electrode plasma in low-pressure gas, In order to change the energy density, the gas pressure of the low-pressure gas in the vacuum housing 1 may be changed.

That is, FIG. 7 shows the relationship between the energy density (J / cm ² ) of the irradiation electron beam and the gas pressure (Torr) of the rare gas (Ar) in the vacuum housing 1 with three different acceleration voltages by the third pulse power supply 18. As shown in the case, it can be seen that the change setting of the energy density by changing the gas pressure is a region where the energy density is relatively high, and the changeable range is larger as the acceleration voltage is higher. From this, on the contrary, it is understood that stable control of gas pressure in the vacuum housing 1 (<± 1%) is important.

  The energy density of the irradiation electron beam can be changed by changing the acceleration voltage by the third pulse power supply 18. However, the acceleration voltage has a short pulse width of about 1 to 5 μs, and the degree of freedom in changing the acceleration voltage. The change of the acceleration voltage is intended to modify the depth of penetration of the irradiated electron beam into the workpiece material and apply the energy of the beam only to the surface layer of the material for the modification process. The third pulse power supply 18 is desirably used repeatedly under a fixed condition that is set in an adjusted manner.

In the surface modification processing apparatus described above, the first pulse power supply 16 controls the excitation current change of the solenoid 5, and the second pulse power supply 17 applies the anode applied to cause glow discharge between the anode 6 and the cathode 8. By combining the voltage change control means and the gas pressure change control means for the rare gas for glow discharge in the vacuum housing 1, the cross-sectional diameter is less than about 60 mm and the energy density is between 0.1 and 10 J / cm ^2. The production member is changed to a predetermined value and irradiated with an electron beam having the same energy density at an interval of about 5 seconds on the same portion of the surface on the end side where the contact of the production member 31A is provided, and the production member The measured values of the surface roughness (Ry μm) of 31A and the thickness (μm) of the copper amorphous layer formed on the surface are the energy density (J / cm ² ) of the electron beam pulse. In contrast, a characteristic curve as shown in FIG. 2 was obtained. In this case, the irradiation time width of the electron beam pulse is about 2 μs.

According to FIG. 2, when the energy density of the irradiation electron beam is increased, the surface roughness (surface flatness) decreases when the pulse of the electron beam having an energy density of about 7 J / cm ² is repeatedly irradiated. The amorphized layer of copper was also thin but firm and showed a flesh-colored or red-blooded metallic color. When the energy density of the electron beam is increased to about 9 to 10 J / cm ² or more, depending on the material, shape, dimensions, etc. of the production section 31A, processing with a previously narrowed linear electron beam is performed. Since the surface becomes rough due to processing phenomena such as cutting, drilling, or welding using deep penetration, it is recommended to use an energy density of the above-mentioned degree.

Under the above-mentioned conditions, the surface layer that has become a beautiful metallic color when irradiated with an electron beam pulse is a parallel beam thin film measurement engineering system using a thin film X-ray diffractometer set to the following conditions, and the X-ray incident angle is set to 0. When measured at a fixed angle of 5 °, a diffraction peak (around 40 ° for copper) derived from the crystal (equiaxial crystal system, face-centered cubic lattice in the case of copper) does not appear, and a faint peak (halo) appears. Therefore, it was estimated that the surface layer was amorphous (amorphous).
Measurement conditions Radiation source CμKα
Optical system Parallel beam optical system
Entrance slit: 0.2 mW
X-ray incident angle: 0.5 °
Receiving slit: 0.23 solar slit Scanning axis 2Θ

  3 (A) and 3 (B) are greatly changed while the contact data of the sample with 10 terminals subjected to the electron beam irradiation process and the sample with 5 terminals not subjected to the irradiation process are being counted. Absent. The resistance was measured by an LCR meter (HEWLETT PACKARD 4284A 20 Hz-1 MHz PRECISION LCRmeters) manufactured by Hewlett-Packard Company. The measurement method was performed by inserting the contact portion of the sample terminal between the upper and lower electrodes and placing the weights (10 g, 50 g, and 100 g) to be described, and a frequency of 20 Hz and a voltage of 10 V. According to the measurement results (A) and (B), most of them are within 1 mΩ, and there is almost no difference in comparison. Therefore, the presence or absence of the electron beam irradiation treatment does not affect the contact resistance value. It has been.

Other environmental tests, etc.
(1) High temperature (heat resistance) test,
The sample is left for 120 hours in a temperature environment of 120 ° C., and then the electric resistance is measured.
The surface of the sample subjected to the electron beam irradiation treatment was not changed by a visual test, and the contact resistance value was not changed.

(2) Low temperature (cold resistance) test,
After leaving at −50 ° C. for 120 hours, after returning to room temperature, the contact resistance is measured.
There is no particular change.

(3) Temperature resistance test,
The sample is placed at a humidity of 90 to 95% at 60 ° C. and left at room temperature for 30 minutes while being energized with DC 12 V, and then the contact resistance is measured.
While the data is being aggregated, it has not changed significantly.

(4) salt spray test,
The treatment of spraying 5% saline for 2 hours and leaving it in a humidity environment of 90 to 95% at 40 ° C. for 22 hours is repeated four times.
The result is visually altered. Data is being collected.

(5) Abrasion resistance test,
Not implemented.

  As described above, the technology of the present invention is still under development, and is only applied to pure copper as a contact material for connector terminals and measured and confirmed a few performances. Amorphization (amorphization) technology forms part of the solid-phase reaction method that amorphizes the crystal surface by ion bombardment, which is called special, compared to the conventional liquid-phase freezing method and vapor-phase freezing method. The development is expected.

  And according to the present invention, copper alloy such as brass, phosphor bronze, beryllium copper, and white as a terminal material for connectors, and surface treatment such as nickel plating for copper barrier on a part of the surface of these copper alloys. It has a high probability of being effective when applied to applied terminal materials, and in addition to other electrically conductive materials and electrode materials such as iron or iron-based alloys, titanium or titanium-based alloys, and to contacts and contact materials. The application of is also considered.

  The present invention can be used in place of a surface treatment in manufacturing a connector for electrically connecting electrical circuits or devices.

The fragmentary top view of the production member of one Example of the terminal for connectors used as the process target object of this invention. The characteristic curve figure which shows the influence which the processing of this invention has on the surface roughness of a production member, and the state of a formed thin film. (A) is a contact resistance measurement table of a sample of one embodiment of the present invention, and (B) is a measurement table of a sample of a conventional example. The front sectional view showing an example of the surface modification processing device by the large area electron beam pulse of the conventional example. FIG. 5 is a discharge characteristic diagram of three pulse power sources of the apparatus of FIG. 4. Explanatory drawing of the magnetic field formation state similarly in the apparatus of FIG. FIG. 5 is a characteristic diagram showing the relationship between the energy density of the irradiation electron beam and the gas pressure (Torr) of the apparatus shown in FIG. 4 for different acceleration voltages.

Explanation of symbols

31 Band plate material 31A Production member 31-1, 31-2, 31-3, ... 31-n Connector terminal

Claims (5)

  Irradiation on the surface of the connector terminal made of copper or a copper alloy has an energy density at which the surface layer part is in a predetermined dissolved state by irradiation, and the irradiation is limited to an energy irradiation amount that re-solidifies immediately after the dissolved surface layer part is dissolved. A method for surface modification of a connector terminal, comprising irradiating a pulse of an electron beam with a short time at least once to form a copper amorphous layer on the surface portion. At least on the surface portion that becomes the contact surface of the connector terminal made of copper, copper alloy, or copper or copper alloy plated with the required metal or alloy,
The diameter Lr of the cross section perpendicular to the irradiation axis is Lr = x × 10 mm (where x = 0.1, 0.2, 0.3,... 0.5,... 0.8,. 1.0, 2.0, ... 5.0, ... 7.0), the energy density Ed is, Ed = 0.1~10J / cm ^2, a pulse beam of the pulse time width .tau.s is, .tau.s = A surface modification processing method for a connector terminal, characterized in that an electron beam pulse of 0.05 to 5.0 μs is irradiated at least once to form a copper amorphous layer as an electrical contact surface on the surface portion. .   The surface of a connector terminal made of copper or a copper alloy has an energy density at which a surface layer portion is melted by irradiation, and an electron beam with a short irradiation time limited to an energy amount that the melted surface layer portion resolidifies after melting. A connector terminal, wherein the surface is finished by irradiating a pulse at least once to form a copper amorphous layer on the surface portion. At least a surface portion to be a contact surface of a connector terminal made of copper, a copper alloy, or a copper or copper alloy plated with a required metal or alloy,
The diameter Lr of the cross section perpendicular to the irradiation axis is Lr = x × 10 mm (where x = 0.1, 0.2, 0.3,... 0.5,... 0.8,. 1.0, 2.0, ... 5.0, ... 7.0), the energy density Ed is, Ed = 0.1~10J / cm ^2, a pulse beam of the pulse time width .tau.s is, .tau.s = A connector terminal comprising: a surface of a copper amorphous layer serving as an electrical contact surface formed by irradiating a pulse of an electron beam of 0.05 to 5.0 μs at least once or more to form a copper amorphous layer on the surface portion. .   A contact part of an electrical connection such as a connector, plug, jack, socket, switch, or relay, the contact part or the whole being made of copper or a copper alloy, iron or an iron alloy, or titanium or a titanium alloy In the electronic mechanism component, the surface of the contact portion is used as an irradiation beam, the surface layer portion has an energy density for melting, and the melting surface layer portion is limited to an irradiation energy amount that resolidifies in a very short time after melting. The surface is finished by irradiating a pulse of an electron beam with a short irradiation time at least once to form an amorphous layer of a contact metal member with improved surface roughness on the surface layer portion. Contact for electronic mechanism parts.

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